Method of finning



g 1-943- w. VAN AMERONGEN srm. 2,326,418

' METHOD OF FINNING 2 Sheets-Sheet 2 fis- 3.

Filed Feb. 28, 1941 HII FIG. 1

- INVENTOR5 Mam/ 1 lwvflMsko/vasn JbH/v N 80 YCE ATTORNEY.

Patented Aug. 10, 1943 METHOD OF FINNING William van Amerongen and John N. Boyce, Akron, Ohio, assignors to The Technical Casting '& Manufacturing 00., Akron, Ohio, a corporation of Ohio Application February 28, 1941, Serial No. aspect (oi. 22-m n I 9 Claims.

This invention relates to heat radiating firmin for use in heat interchangers and more particularly to a new and improved method of providing cylinder barrels of internal combustion engines with cooling fins, and to the article produced thereby.

It is among the objects of the present invention to provide a new-and improved method of providing a cylinder barrel with finning wherein the joint or union between the cylinder wall and the fins are of such a character as ,to provide for an effective and efficient flow of heat from the. wall of the cylinder barrel to the surrounding atmosphere.

A further object of the invention is to provide a method of securing preformed fins made of a high heat conducting material, such as aluminum, to a cylinder barrel composed of a high strength material, such as steel, with a joint which is substantially free of any insulating mediums which would preclude the free flow of heat from the wall of the cylinder barrel to the fins.

A still further object of the invention is to provide a cylinder barrel having substantially increased heat dissipating surface area without unduly increasing the weight of the engine member.

Other objects of the invention, not at this time more particularly enumeratedwill become more apparent as the nature of the invention is better understood from the following detailed description taken in conjunction with the accompanying drawings, wherein,

Figure 1 is a fragmentary side elevational view or" a cylinder barrelhaving a plurality of preformed cooling fins mounted on the exterior wall thereof,

Figure 2 is a sectional view, taken on the line 2-2 of Figure l,

Figure 3 is an enlarged fragmentary sectional view, taken on the line 3-3 of Figure 2,

Figure l is a top plan view of apparatus which may be employed in practicing the subject invention, V

Fisulre 5 is a fragmentary elevational view, partly in section, taken on. the line 5-5 of Fi we I Figure 6 is a fragmentary detail, partly in sec- I tion, taken on the line 3-6 of Figure 4,

Figure '7 is a fragmentary sectional detail, taken on the line 1-1 of Figureii,

Figure 8 is a detail, taken onl the line 8-8 of Figure 4,

Figure 9 i a 99 of Figure 5.

sectional view, taken on the line With reference to Figures 1 to 3, inclusive, of

the drawings, the numera1 iii designates a cylinder barrel of an air-cooled internal combustion engine, having the usual hold down flange it, and the usual threads i! on to which the cylinder head (not shown) is threaded and shrunk in the usual manner. The outer surface of the barrel 1 is provided with a plurality of preformed, relatively thin, cooling line it, the inner edge portions of which are embeddedin a cast muff it, which is bonded to the exterior wall of the cylinder. The joint between the wall of the cylinder i5 and the mutt i9 is characterized by having high thermal comzluctivityv thereacross. The number, size, and distribution oi the fins mounted on the exterior of the barrel wall can be varied to provide sumcient heat dissipating surface area.

to meet the desired cooling requirements of the particular cylinder barrel. In providing cooling fins on a cylinder barrel having a diameter of six inches, we have found with fin members twenty-five thousandths of an. inch in thickness and extending outwardly from the barrel about one and one-fourth inch and spaced apart a distance of fifty thousandths of an inch along the barrel wall, a fifty per cent increase in cooling efiiclency over prior types of finned barrels was obtained. Although the fin members may be made of any suitable metal having high thermal conductivity, we have found that where the combination of lightness and rapid heat dissipation is an essential element in the finished article, aluminum has proven to be most acceptable for the od of the present invention for providing cylinder barrel by suitably masking the remaining sur-' face. In cleaning, the barrel is immersed in an electrolytic bath containing caustic soda, then into a solution of sodium cyanide following which it is washed in clear water. Following the cleaning operation, the barrel is pickled in a solution of hydrochloric acid and then washed in clear water.

The cleaned wall portion of the barrel is then provided with a coating of a cadmium alloy. In

applying this coating, the barrel wall is coated witha flux consisting of a solution containing" three parts of zinc chloride and one part of sodium chloride and then the thus treated barrel ing bath may be formed by providing molten cadmium in a suitable container under a surface blanket of fluxing material which is preferably zinc chloride. After the bath has been so prepared, sheet nickel is introduced therein through the flux in amounts sufficient to yield a cadmium alloy containing approximately 0.1% to of nickel, although from 1.3% to 1.75% has been found to be most desirable. Zinc the tendencyof the cadmium to vaporize. The cadmiumizing bath is formed substantially as disclosed in the patent to Carl E. Swartz, No. 2,040,282, issued May 12, 1936. It has also been found that the addition of tin not exceeding five percent to the cadmiumizing bath is helpful to prevent subsequent oxidation of coating on the cylinder barrel during the casting operation.

While the barrel is immersed in the cadmium bath, it is preferably rotated to insure a suincient and uniform coating ofcadmium alloy on the surface thereof. This rotation is continued as the barrel is withdrawn from the bath and thereafter while the coating is cooling, to provide a thin and uniform coating, free from'dross or other extraneous matter.

The preformed fins, which may or may not have their inner edge portion provided with a thin coating of zinc, are assembled in a suitable mold and the mold and fins heated to a predetermined temperature, preferably between 1000 F. and 1060" F. During the time that the mold and fins are being heated, the barrel is also heated preferably to a temperature of between 450 F. and 600 F. When the barrel and the mold have been heated to the predetermined temperatures, the barrel is inserted within the mold and the assembly prepared -for casting the muff. When the barrel is so disposed within the mold, the fins carried by the mold are positioned in proper spaced relation along the coated portion of the barrel wall. Immediately after the barrel'has been inserted in the mold, molten aluminum at a temperature of between 1300 F. and 1450- F. is cast into the cavity defined by the inner edge portions of the fins and the barrel wall, completely filling the same. The molten metal may be cast under pressure with certain types of apparatus, or it may be cast under gravity feed and the mold assembly vibrated or rapidly rotated as in centrifugal casting practice, to insure a solid porosity freemufl'.

The cadmium alloy coating on the wall serves to bond the thus formed aluminum muff to the barrel,.and the edge portions of the fins being secured within the muff, a substantially unitary structure is provided. The barrel is then removed from the mold and permitted to 0001,

after which it is finished and ready for use. p,

With reference to Figures 4 to 9, inclusive, of the drawings, there is illustrated a form of appar'atus which may be used in conjunction with the practice of the present invention. This apparatus includes a base having an upstanding cylindricalbearing post 2!. The bearing post 2| is adapted to rotatably receive a hollow housing member 22 secured to the lower surface of the spaced frame members 23. Extending upwardly from between the frame members 23 are spaced supporting. members 24 and 25 which are adapted to receive thereover the barrel IS with the lower edge resting upon the upper surface of 15 which terminates in an arcuate wall 36.

site ends of lug I is immersed in a cadmiumizing bath. The coat: the "frame members 23. The mold, generally.

indicated by the number 28, is adapted to encase the barrel and be supported in proper relative position to the outer surface of the barrel wall 5 by the hold down flange [6 of the barrel.

The mold 26 is preferably made in quadrants 21, 28, 29, and 30, which are secured in assembled relation by means of bolts 3| extending through outwardly extending ears 32 formed on adja- 10 cent portions of the assembled quadrants. Each inan amount approximately .05% of the total is added to the bath which serves to eliminate of the quadrants comprises a vertical arcuate wall 33 terminating in inwardly extending flanges 3 The lower portion of the arcuate wall 33 is formed with a bottom wall portion 35 Extending outwardly from the wall 36 and formed in the bottom wall portion 35 is a recess 31.

Each of the quadrants are adapted to receivein stacked relation on the upper surface of the 20 bottom wall portion 35 a plurality of spacer members 38 which are provided with notched peripheral corners adapted to engage the inwardly extending flanges 34 of the wall portion 33. The fin members are adapted to be posi- 5tioned or spaced relative to each other by the spacers 3B, thethickness thereof defining the distance between adjacent fins when the same are secured to the barrel wall.

The quadrants are adapted to be supported upon the hold down flange I6 of the cylinder barthe barrel. When the mold 26 with the spacers and fins disposed therein is assembled about the barrel l5, there is provided a mold cavity 40 about that portion of the barrel wall which has been previously coated with the wetting metal, the bot- 40 tom of this mold cavity 40 is in communication with the recess 31, the latter serving as a gate or runner for supplying molten metal to the mold cavity 40. Extending through the'quadrant 29 is an orifice 4| which effects communication be- 45. tween the runner 31 and the discharge orifice 42 of/the sprue 43. Y

The sprue 43 is maintained in proper pouring position with respectto the quadrant 29 by means of a C-clamp 44, the ends of which engage oppo- 45 formed integrally with the side wall of the quadrant 28. Cooperating with the G-clamp 44 is a shoe 48 engaging the sprue 4: and a set screw 41 for adjusting the relative position of the clamp, and shoe 46. Any suitable clamping means may beemployed to hold the cylinder barrel, mold'and' fins together dur ing the casting of the muff; for example, a plurality of clamping members "which bear upon the ring 18 disposed on the top of the mold quad- 0 rants may be employed.

Although we have illustrated apparatus wherein the metal may be poured into the mold cavity 40 to form the muif l9 through the sprue 43 by gravity feed, where it is preferable, the spruefmay be dispensed with and the orifice 4| connected to the discharge port of any suitable type of pressure casting device.

For removing the mold 26 from the barrel, the

opposed quadrants 28'and 30 are provided with 7 outwardly extending lugs 48 which are adapted to receive the free ends of c-shaped bracket members 43 which are mounted upon the upper end of guiding members 50. The upper end of the members are bifurcated to receive the blocks II which are pinned on the ends of adJusting screws 52. The adjusting screws 52 are threadedly received in the threaded ends 53 of posts 54 extending upwardly from the frame member 23.

Adjustment of the screws 52 is effected by means of any suitable wrench adapted to engage the ends 55 thereof. Theguiding members 50 serve to maintain the mold-quadrants in a substantially horizontal position.

Where gravity pouring is employed, we have found that it may be preferable to vibrate or rapidly rotate the mold and barrel during the casting of the muff to insure a solid porosity-free muff. For this purpose there is 'illustrated,'

mounted on the base 20, adjacent one end of the frame 23, mechanism for oscillating or vibrating the frame'23 and the assembled mold and barrel carried thereby. Such mechanism comprises an upstanding post 56 carrying a cylindrical lug 51 which serves to receive one end of a spring 58, the opposing end of which is adapted to engage the side wall of the frame 23. On the opposite side of the frame 23 and in alignment with the post 56 is a bearing member 59 which slidably receives a horizontally extending shaft 60, one end of which seats against a bearing plate 6| carried on the frame 23. The opposite end of the shaft 60 is adapted to engage an eccentric t2 pinned to a shaft 63 rotatably supported in a bearing member 54. The shaft 63 is adapted to be rotated by means of a sheave 65 connected to any suitable source of power, not shown.

Having thus described our invention so that those skilled in the art may be able to understand and practice the same, what we desire to obtain by Letters Patent is defined in the appended claims.

What we claim is:

1. The method of produci alloy cylinder barrel for an air-cooled internal combustion engine with aluminum cooling fins on the exterior surface thereof which includes the steps of providing that portion of the exterior surface of the barrel which is to receive the cooling fins with a coating of an alloy consisting of cadmium containing from 0.1% to nickel,

' of providing that portion of the exterior surface a ferrous metal assembling preformed ring-like aluminum fin j members in spaced relation with their openings in coaxial alignment within. a permanent mold, heating said mold to a predetermined temperature, inserting said barrel into the mold cavity tions of the fin members.

2. The method of producing a ferrous metal alloy cylinder barrel for an air-cooled internal combustion engine with aluminum cooling fins of the barrel which is to receive the fins with a coating of an alloy consisting of from 1.3% to 1.75% nickel, approximately .05% zinc and the balance cadmium, assembling preformed ringlike aluminum fin members in spaced relation with their openingsin coaxial alignment within a permanent mold, heating said mold to a predetermined temperature, inserting said barrel into the mold cavity defined by the opening in said fin members, and thensecuring the fin members to the barrel by casting asleeve about said f barrel, said sleeve being bonded to the wall of the cylinder barrel and having the inner edge portions of the fin members embedded therein.

4. The method of producing a cylinder barrel for an air-cooled internal combustion engine with cooling fins on the exterior surface thereof, which includes the steps of treating that portion of the barrel wall which is to receive the fins with a pickling solution and then an alloy consisting of cadmium containing from 0.1% to 10% nickel, assembling preformed ring-like aluminum fin members in spaced relation with their openings in coaxial alignment within a permanent mold, heating said barrel and said mold and fins to different predetermined temperatures, and then inder barrel and having the inner edge portions of the fin members embedded therein.

5. The method of producing a ferrous metal alloy cylinder barrel for an air-cooled internal combustion engine with aluminum cooling fins on the exterior surface thereof whichincludes the steps of treating that portion of the barrel wall which is to receive the fins with a pickling solution and then an alloy consisting of cadmium containing from 0.1% to 10% nickel, heating said barrel to a predetermined temperature, assembling preformed ring-like aluminum fin members in spaced relation with their openings in coaxial on the exterior surface thereof which includes the steps of treating that portion of the barrel wall which is to receive the fine with an alloy' consisting of cadmium containing from 0.1% to 10% nickel, assembling preformed ring-like aluminumfin members in spaced relation with their openings in coaxial alignment within a permanent mold, heating said mold to a predetermined temperature, insertingsaid barrel into the 'mold cavity defined by the opening in said fin memalignment within a permanentmold, heating said mold to a predetermined temperature, inserting said barrel into the mold cavity defined by the opening in said fin members, securing thefin -membersto the barrel by casting an aluminum sleeve about said barrel, and vibrating the mold during the casting of the sleeve, said sleeve being bonded to the wall of the cylinder barrel and having the inner edge portions'of the fin members embedded therein.

6. The method of producing a ferrous metal alloy cylinder barrel for an air-cooled internal' combustion engine with aluminum cooling fins on a portion of the exterior surface thereof, which includes the steps of pickling that portion of the exterior surface of the barrel which is to receive the fins, coating said portion with an alloy consisting of from 1.3% to 1.75% nickel, approximately .05% zinc and the'balance cadmium, assembling preformed ring-like aluminum fin members in spaced relation with their openings in coaxial alignment within a permanent mold, heating said mold to a predetermined tern-perature, inserting said barrel into the mold cavity defined by the opening in said fin members, securing the fin members to the barrel by casting an aluminum sleeve about aid barrel, and vibrating the mold during th casting of the sleeve,

said sleeve being bonded to the wall of the cylinder barrel and having the inner edge portions of the fin members embedded therein.

7. The method of producing a ferrous metal alloy cylinder barrel for an air-cooled internal combustion engine with aluminum cooling fins on the exterior surface thereof, which includes the steps of pickling that portion of the exterior surface of the barrel which is to receive the fins, coating said portion with an alloy consisting of from 1.3% to 1.75% nickel, approximately 115% zinc and the balance cadmium, heating said barrel to a predetermined temperature, assembling preformedring-like aluminum fin members in spaced relation with their openings in coaxial alignment within a permanent mold, heating said mold to a predetermined different temperature, inserting said barrel into the mold cavity defined by the opening in said fin members, and then securing the fin members to the barrel by casting an aluminum sleeve about said barrel, said sleeve being bonded to the wall of the cylinder barrel and having the inner edge portions of the fin members embedded therein.

8. A method of producing a ferrous metal cylinder barrel for an air cooled internal combustion engine with aluminum cooling fins on the exterior surface thereof, which includes the steps of providing that portion of the exterior surface of the barrel which is to receive the cooling fins with a coating of an alloy consisting of cadmium containing from 0.1% to 10% nickel, heat- 7 in said barrel to a predetermined temperature,

assembling preformed ring-like aluminum fin members with their openings in coaxial alignment in a permanent mold and heating the assembled mold and fins to a temperature of between 1000 F. and. 1060 F., assembling said barrel within said mold, securing the fin members to the barrel by casting molten aluminum into the cavity defined by the barrel wall and the inner edge portions of the fins, and vibrating the mold during the casting of the metal,

9. The method of producing a ferrous metal cylinder barrel for an air-cooled internal combustion engine with aluminum cooling fins on the exterior surface thereof, which includes the steps of providing that portion of the exterior surface of the barrel which is to receive the cooling fins with a coating of an alloy consisting of cadmium containing from 0.1% to 10% nickel, heating said coated barrel to a temperature of between 450 F. and 600 F., assembling preformed ring-like aluminum fin members with their openings in coaxial alignment in a permanent mold and heating the assembled mold and fins to a temperature of between 1000 F. and 1060 F., assembling said barrel within said mold while at said temperatures, and then casting molten aluminum into the cavity defined by the barrel wall and the inner edge portions of the fin members, and vibrating the mold during the casting of the metal, thereby bonding the preformed fins to the wall of the cylinder barrel.

WILLIAM VAN AMERONGEN. JOHN N. BOYCE. 

